A novel technique that enables coherent detection of spontaneous Brillouin scattering in the radio-frequency region with excellent long-term stability has been demonstrated for distributed measurements of temperature and strain in long fiber. An actively stabilized single-frequency Brillouin fiber laser with extremely low phase noise and intensity noise is used as a well-defined, frequency-shifted local oscillator for the heterodyne detection, yielding measurements of spontaneous Brillouin scattering with high frequency stability. Based on this approach, a highly stable real-time fiber sensor for distributed measurements of both temperature and strain over long fiber has been developed utilizing advanced digital signal processing techniques.
© 2007 Optical Society of AmericaFull Article | PDF Article
Sally M. Maughan, Huai H. Kee, and Trevor P. Newson
Opt. Lett. 26(6) 331-333 (2001)
Daisuke Iida and Fumihiko Ito
Appl. Opt. 48(22) 4302-4309 (2009)
Carlos A. Galindez, Francisco J. Madruga, and Jose M. Lopez-Higuera
Opt. Express 19(20) 18917-18926 (2011)